C. Santamaría

Significance of CIELAB parameters in the routine analysis of red wines

Correlations have been sought among different parameters (total polyphenols, anthocyanins and flavonoids, monomeric anthocyanins, Zn, Cu, Mn, and Fe) analyzed in two consecutive vintages of a Tempranillo wine. A comparative study of those parameters with color characteristics (both CIELAB and Glories parameters) is presented for these wines. Principal Component Analysis (PCA) has showed the existence of a close relationship between CIELAB parameters and polyphenol concentrations, whereas no correlation could be found with classic color parameters but in the expected case of Color Intensity (CI). An equation is proposed that allows the concentration of total polyphenols to be estimated as a function of total anthocyanins, cyanidin-3-glucoside (Cy-3-gluc), and petunidin-3-glucoside (Pt-3-gluc) concentrations. Chromatographic fractioning of wine samples evidenced the specific interaction of both Pt-3-gluc and Cy-3-gluc with Fe, Zn, and Cu.

Application of microwave digestion and ICP-MS to simultaneous analysis of major and trace elements in aerosol samples collected on quartz filters

A microwave digestion method in a closed vessel was developed for the simultaneous determination of trace and major elements, with the highest possible recoveries, in atmospheric aerosols using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). This method was developed to quantify the concentration of Na, Mg, Al, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Cd, Sb, Cs, Ba, La, Ce and Pb present in quartz filters containing particulate matter (PM10). The performance of the procedure was evaluated by analysis of the standard reference material NIST 1633b and CTA-FFA-1. Different combinations of nitric acid (HNO3), hydrogen peroxide (H2O2), hydrofluoric acid (HF) and hydrochloric acid (HCl) were tested to improve the recovery factors for the studied elements. The addition of a large amount (3 mL) of HF was required to fully dissolve the quartz filters. This fact made difficult the obtention of high recoveries for alkali (Rb, Cs), alkaline earth (Mg, Ca, Ba), and rare earth (La, Ce) elements, which showed the lowest recoveries. In this study three different digestion methods were assessed using a closed evaporation system, the addition of boric acid and a mixture of both procedures to minimize the effects of residual fluoride.